He was born in Qal'at Bani Hammad in modern-day Algeria, capital city of the Sanhaja Hammadid dynasty of the central Maghreb,[2][3][4][5][6] and is therefore sometimes called "ha-Kala'i.

[11] When Alfasi was himself on the point of death, he recommended as his successor in the Lucena rabbinate, not his own son, but his pupil Joseph ibn Migash.

Alfasi transcribed the Talmud's halakhic conclusions verbatim, without the surrounding deliberations; he also excludes all Aggadic (non-legal, homiletic) matter as well as discussion of the halakha practicable only in Land of Israel.

Firstly, "the Rif" succeeded in producing a Digest, which became the object of close study, and led in its turn to the great Codes of Maimonides and of Rabbi Joseph Karo.

At the close of the Middle Ages, when the Talmud was banned in Italy, Alfasi's code was exempted so that from the 16th to the 19th centuries his work was the primary subject of study of the Italian Jewish community.

In contradistinction to the Ashkenazi approach, the Sephardim sought to simplify the Talmud and free it from casuistical detail;[8] see for example Hananel ben Hushiel.